System and Method for a Long-Term Evolution (LTE)-Compatible Subframe Structure for Wideband LTE

ABSTRACT

A system and method of scheduling transmissions. A wireless device such as an eNodeB (eNB) may schedule a transmission of a wideband (WB) signal on a micro-frame selected from a plurality of WB micro-frames of a WB carrier. A narrowband (NB) subframe may span a portion of the selected WB micro-frame in the frequency-domain, and the selected WB micro-frame may overlap at least a portion of the NB subframe in the time-domain. The WB signal and an NB signal may be transmitted over the WB micro-frame and the NB subframe in accordance with a first numerology and a second numerology, respectively. A WB subframe may be divided into a plurality of micro-frames. The transmission direction of the WB micro-frame may be scheduled according to a transmission rule based on the contents of a payload in the NB subframe.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is a continuation of U.S. patent applicationSer. No. 15/162,202, filed on May 23, 2016 and entitled “System andMethod for a Long-Term Evolution (LTE)-Compatible Subframe Structure forWideband LTE”, which claims priority to U.S. Provisional Application No.62/168,255, filed on May 29, 2015 and entitled “System and Method for anLTE-Compatible Subframe Structure for Wideband LTE”. The aforementionedapplications are hereby incorporated by reference herein as ifreproduced in their entireties.

TECHNICAL FIELD

The present invention relates generally to managing the allocation ofresources in a network, and in particular embodiments, to techniques andmechanisms for a long-term evolution (LTE)-compatible subframe structurefor wideband LTE.

BACKGROUND

The current spectrum allocation for cellular systems is becominginadequate in capacity as the number of users and the amount of trafficincrease. While more frequency bands can be included for the cellularcommunication, these frequency bands are usually higher in frequency(e.g., 3.5 gigahertz (GHz)-6 GHz) than the traditional cellular bands(e.g., 1100 MHz to 2.5 GHz), typically larger in contiguous bandwidth(e.g., up to 400 MHz) compared to the typical maximum of 20 MHz, andoften unpaired such that only one band may be available for transmissionand reception.

SUMMARY OF THE INVENTION

Technical advantages are generally achieved, by embodiments of thisdisclosure which describe a system and method for an LTE-compatiblesubframe structure for wideband LTE.

In accordance with an embodiment, a method for scheduling transmissionsis provided, as may be performed by an eNodeB (eNB). In this example,the method includes selecting a wideband micro-frame from a plurality ofwideband micro-frames of a wideband carrier. A narrowband subframe spansa portion of the selected wideband micro-frame in the frequency-domain,and the selected wideband micro-frame overlaps at least a portion of thenarrowband subframe in the time-domain. The method further includesscheduling a wideband transmission to be performed on resources of theselected wideband micro-frame in accordance with a transmissiondirection of signaling carried in the portion of the narrowband subframethat overlaps the selected wideband micro-frame in the time-domain. Adownlink wideband transmission is scheduled to be performed on theresources in the selected wideband micro-frame when downlink signalingis carried in the portion of the narrowband subframe that overlaps theselected wideband micro-frame in the time-domain. An uplink widebandtransmission is scheduled to be performed on the resources in theselected wideband micro-frame when uplink signaling is carried in theportion of the narrowband subframe that overlaps the selected widebandmicro-frame in the time-domain. The method further includes signalingthe wideband transmission scheduling to a user equipment (UE). Anapparatus for performing this method is also provided.

In accordance with another embodiment, a method for wirelesscommunications is provided, as may be performed by wireless devices. Themethod includes transmitting, by a first wireless device, to a secondwireless device a wideband subframe consisting of N micro-frames. The Nmicro-frames have a combined duration that is equal to a duration of asingle narrowband subframe. The method further includes transmitting, bythe second wireless device, to the first wireless device anacknowledgement or a negative acknowledgement on the earliest availablemicro-frame at least a predetermined number of subframes after thecorresponding wideband subframe. An apparatus for performing this methodis also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a diagram of an embodiment wireless communicationsnetwork;

FIG. 2A-2C illustrate a diagram of an embodiment wideband (WB)-LTEarchitecture;

FIG. 3 illustrates a flowchart of an embodiment method for scheduling aWB signal;

FIG. 4 illustrates a diagram of an embodiment scheduling scheme for WBsignals;

FIG. 5 illustrates a flowchart of an embodiment method for transmittingWB signals;

FIG. 6 illustrates a diagram of three embodiment schemes for definingtransmission time intervals (TTIs) of WB signals;

FIG. 7 illustrates a diagram of an embodiment micro-frame structure forWB signals;

FIG. 8 illustrates a diagram of an embodiment WB subframe;

FIG. 9 illustrates a diagram of an embodiment WB signal structure withcarrier aggregation;

FIG. 10 illustrates a diagram of an embodiment processing system; and

FIG. 11 illustrates a diagram of an embodiment transceiver.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of embodiments of this disclosure are discussed indetail below. It should be appreciated, however, that the conceptsdisclosed herein can be embodied in a wide variety of specific contexts,and that the specific embodiments discussed herein are merelyillustrative and do not serve to limit the scope of the claims. Further,it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of this disclosure as defined by the appended claims.

Some frequency bands that were not utilized for cellular systems arebeing considered to be used for future cellular systems. To operate atthese frequencies, one option is to enhance the physical layer of theexisting LTE systems to operate with larger bandwidths. This design mayreduce latency and overhead, as well as increase throughput. Thus, acompatible frame structure that accommodates these frequency bands isdesired.

Disclosed herein is an embodiment LTE-compatible subframe structure forwideband LTE that allows a wideband (WB) signal and a narrowband (NB)signal to be simultaneously transmitted in accordance with a firstnumerology and a second numerology, respectively. The NB signal may betransmitted over a legacy LTE carrier bandwidth and the WB signal may betransmitted over the LTE frequency band in addition to previously unusedfrequency sub-bands. Both the WB signal and the NB signal may betransmitted simultaneously over the same center frequency with the NBsignal spanning a subset of subcarrier frequencies spanned by the WBsignal. A WB subframe may be further divided into a plurality ofmicro-frames, while a total duration of the WB subframe stays the sameas a duration of a single NB subframe.

Micro-frames of a WB subframe may be scheduled according to atransmission rule based on the contents of a payload in an NB subframe.For example, the transmission rule may prohibit uplink (UL)transmissions from being scheduled on the one or more micro-frames ofthe WB subframe when the payload of the NB subframe carries downlink(DL) data, and vice versa. One or more leading micro-frames of the WBsubframe may be statically assigned to carry DL transmissions, and oneor more trailing micro-frames of the WB subframe may be dynamicallyassigned to carry DL transmissions, UL transmissions, or combinationsthereof. On the other hand, one or more leading micro-frames of the WBsubframe may be statically assigned to carry UL transmissions, and oneor more trailing micro-frames of the WB subframe may be dynamicallyassigned to carry UL transmissions, DL transmissions, or combinationsthereof. These and other aspects are disclosed in greater detail below.

FIG. 1 illustrates a network 100 for communicating data. The network 100comprises a base station 110 having a coverage area 112 a plurality ofmobile devices 120 (120 a, 120 b), and a backhaul network 130. As shown,the base station 110 establishes uplink (dashed line) and/or downlink(dotted line) connections with the mobile devices 120, which serve tocarry data from the mobile devices 120 to the base station 110 andvice-versa. Data carried over the uplink/downlink connections mayinclude data communicated between the mobile devices 120, as well asdata communicated to/from a remote-end (not shown) by way of thebackhaul network 130. As used herein, the term “base station” refers toany component (or collection of components) configured to providewireless access to a network, such as an enhanced Node B (eNB), amacro-cell, a femtocell, a Wi-Fi access point (AP), or other wirelesslyenabled devices. The terms “eNB” and “base station” are usedinterchangeably throughout this disclosure. Base stations may providewireless access in accordance with one or more wireless communicationprotocols, e.g., long term evolution (LTE), LTE advanced (LTE-A), HighSpeed Packet Access (HSPA), Wi-Fi 802.11a/b/g/n/ac, etc. As used herein,the term “mobile device” refers to any component (or collection ofcomponents) capable of establishing a wireless connection with a basestation, such as a user equipment (UE), a mobile station (STA), andother wirelessly enabled devices. In some embodiments, the network 100may comprise various other wireless devices, such as relays, low powernodes, etc.

FIG. 2A illustrates an embodiment wideband (WB)-LTE architecture thatcan accommodate legacy UEs. Legacy UEs may transmit and receive an NBsignal 220 over the legacy LTE carrier bandwidth. Next generation UEsmay transmit and receive a WB signal 210 over the WB LTE carrierbandwidth. As shown, the NB signal 220 spans a subset of subcarrierfrequencies spanned by the WB signal 210. FIG. 2B illustrates the WBsignal 210 (individually), and FIG. 2C illustrates the NB signal 220(individually). As shown, the WB signal 210 may include a zero powerportion 212 and two non-zero power portions 214, 216; the zero powerportion 212 of the WB signal 210 may span the same set of subcarrierfrequencies as the NB signal 220. The NB signal 220 may span a subset ofsubcarrier frequencies spanned by the zero power portion 212. The zeropower portion 212 of the WB signal 210 may be positioned in between thenon-zero power portions 214, 216 of the WB signal 210 in the frequencydomain. In the example, the zero power portion 212 of the WB signal 210spans the center frequency of the WB signal 210. In other examples, thezero power portion 212 of the WB signal 210 does not span the centerfrequency of the WB signal 210. In such examples, the zero power portion212 may be partially offset from the center carrier frequency of the WBsignal 210 such that one of the non-zero power portions 214, 216 iswider than the other. Alternatively, the zero power portion 212 may belocated at the edge of the WB LTE bandwidth such that the WB signal 210includes a single non-zero power portion. Other configurations are alsopossible.

LTE operations over the legacy carrier bandwidth may stay compliant withexisting LTE standards. The overall radio frame structure of the WBsignal 210 may also be compliant with the existing LTE standards. Table1 lists some possible bandwidth configurations for the WB signal 210.

TABLE 1 Sample Rate (Msamp/s) FFT Size Bandwidth, MHz PRBs 30.72 2048 20100 61.44 4096 40 200 122.88 8192 80 400 245.76 16384 160 800 491.5232768 320 1000

FIG. 3 illustrates an embodiment method 300 for scheduling a WB signal,as may be performed by a wireless device such as a controller (e.g.,base station, central controller, etc.). As shown, the method 300 beginsat step 310, where a WB micro-frame is selected by the controller from aplurality of WB micro-frames of a WB carrier. A NB subframe may span aportion of the selected WB micro-frame in the frequency-domain, and theselected WB micro-frame may overlap at least a portion of the NBsubframe in the time-domain. Thereafter, the method 300 proceeds to step320, where a WB transmission is scheduled by the controller to beperformed on resources of the selected WB micro-frame in accordance witha transmission direction of signaling carried in the portion of the NBsubframe that overlaps the selected WB micro-frame in the time-domain. Adownlink WB transmission may be scheduled to be performed on theresources in the selected WB micro-frame when downlink signaling iscarried in the portion of the NB subframe that overlaps the selected WBmicro-frame in the time-domain. Similarly, an uplink WB transmission maybe scheduled to be performed on the resources in the selected WBmicro-frame when uplink signaling is carried in the portion of the NBsubframe that overlaps the selected WB micro-frame in the time-domain.

Subsequently, the method 300 proceeds to step 330, where a WB signal istransmitted over the selected WB micro-frame. The controller maycommunicate the micro-frame scheduling assignments to a UE with thecapability of transmitting and/or receiving WB signals. A wirelessdevice with the capability of transmitting and/or receiving WB signals,such as the controller or a UE, may transmit a WB signal in accordancewith a first numerology. The subset of physical layer parameters used tocommunicate a signal over a carrier are collectively referred to as the“numerology” of the carrier, and may include a combination, or subset,of a transmission time interval (TTI) used to transmit the signal overthe carrier, a symbol duration of symbols transmitted over the carrier,a cyclic prefix (CP) length of symbols transmitted over the carrier, anda sub-carrier spacing between sub-carrier frequencies over which thesignal is transmitted.

The wireless device may transmit an NB signal in accordance with asecond numerology that is different than the first numerology. The WBsignal and at least a portion of the NB signal may overlap in thetime-domain. For example, both the WB signal and the NB signal may betransmitted simultaneously over the same center frequency. As discussedabove, the NB signal may span a subset of subcarrier frequencies spannedby the WB signal.

The first numerology and the second numerology may include a commonsubset of physical layer parameters for communicating over the NBbandwidth and the WB bandwidth. The common subset of physical layerparameters may include a common subcarrier frequency spacing betweensubcarriers in both the NB bandwidth and the WB bandwidth, a commonsymbol duration for symbols in both the NB bandwidth and the WBbandwidth, a common duration of a radio frame, a common duration of asubframe, and/or some other physical layer parameter.

Some features of the cellular systems allow uplink (UL)-downlink (DL)configuration for time division duplexing (TDD) mode to changeperiodically, for example every 10 ms. Alternatively, the UL-DLconfiguration may be chosen from one option in Table 2.

TABLE 2 Uplink- downlink configuration 0 1 2 3 4 5 6 7 8 9 0 D S U U U DS U U U 1 D S U U D D S U U D 2 D S U D D D S U D D 3 D S U U U D D D DD 4 D S U U D D D D D D 5 D S U D D D D D D D 6 D S U U U D S U U D

In Table 2, “D” represents a DL subframe, “U” represents an UL subframe,and “S” represents a special subframe. In current systems, a subframemay be defined as 30,720 samples where the sample rate (1/Ts) is30,720,000 samples/second. In the special subframe, the samples aregrouped into three sets. The first set of samples forms the downlinkpilot timeslot (DwPTS), the second set of samples forms the guard period(G), and the last set forms the uplink pilot timeslot (UpPTS). Thenumber of samples in each set is defined by the standards. The guardperiod allows the device to switch from receiving DL transmissions totransmitting UL transmissions as well as allowing timing advance.

With dynamic switching of the uplink-downlink configuration, one or morecapable UEs may monitor downlink control information (DCI) format 1C todetermine the uplink-downlink configuration for the next radio frame.DCI format 1C is transmitted on the physical downlink control channel(PDCCH) using the common search space rules. There are certainuplink-downlink configurations that can be grouped together, such as((4, 0, 1, 3, 6), (5, 0, 1, 2, 3, 6), (2, 0, 1, 6)).

FIG. 4 illustrates an embodiment scheduling scheme for WB signals.Micro-frames 412 and 421 may be used for control channel transmissions,for example physical downlink control channel (PDCCH). As shown in Case1, when a payload 415 of an NB subframe 410 is scheduled for DLtransmissions, micro-frames 422-428 of a corresponding WB subframe 420may also be scheduled for DL transmissions. In Case 2, when a payload ofan NB subframe 430 is scheduled for UL transmissions, micro-frames of acorresponding WB subframe 440 may also be scheduled for ULtransmissions. In Case 3, when a payload of an NB subframe 450 is empty,micro-frames of a corresponding WB subframe 460 may be scheduled foreither DL or UL transmissions. It should be noted that in someembodiments, some micro-frames of a WB subframe may be scheduled for ULtransmissions, and the remaining microframes of the WB subframe may bescheduled for DL transmissions. Some micro-frames of a WB subframe maybe pre-scheduled, and the remaining micro-frame of the WB subframe maybe scheduled dynamically. In an example, the start symbols of a WBsubframe may be 2× ceiling(control format indicator (CFI)/2) where a CFIindicates the length of the control region (number of symbols used forPDCCH).

A guard interval may be transmitted between the UL micro-frames and DLmicro-frames. The guard interval between micro-frames carrying UL dataand micro-frames carrying DL data in the WB subframe may be defined asone symbol duration, half a symbol duration, or some other duration.Initial access to the WB subframe may be performed by transmitting WBconfigurations over NB subframes. For example, the base station 110 maycommunicate parameters of the WB signal, such as the bandwidth,subcarrier spacing, and/or center carrier frequency of the WB signal, tothe UE 120 a or 120 b over the NB signal. Configurations of the WBsignal may be transmitted in broadcast messages and/or radio resourcecontrol (RRC) messages.

An acknowledgement/negative acknowledgement (A/N or ACK/NACK) may besent by a UE on the earliest available micro-frame at least apredetermined number of subframes after the corresponding DLmicro-frame. The predetermined number may be four, two, or some othernumber. However, for some DL micro-frames, if the next subframe(s) is DLonly, then the A/N may be delayed. A WB device may need to know the NBsubframe configuration, which may be obtained by decoding the NBsignals. Alternatively, the WB capable device may operate in a WB modeonly. In such a case, the NB subframe configuration may need to be knownand/or signaled to WB devices. This could be done, e.g., in a physicalcontrol format indicator channel (PCFICH) in the first micro-frame ofthe first subframe of a radioframe or in some other location.

FIG. 5 illustrates an embodiment method 500 for transmitting WB signals,as may be performed by wireless devices (e.g., eNBs, UEs, etc.). Asshown, the method 500 begins at step 510, where a first wireless devicetransmits to a second wireless device a WB subframe consisting of Nmicro-frames. The N micro-frames may have a combined duration that isequal to a duration of a single NB subframe. Thereafter, the method 500proceeds to step 520, where the second wireless device transmits to thefirst wireless device an acknowledgement/negative acknowledgement on theearliest available micro-frame at least a predetermined number ofsubframes after the corresponding wideband subframe.

FIG. 6 illustrates three embodiment WB transmission time intervals(TTIs) 601, 602, 603. A TTI of the WB signal may have the same durationas, or a different duration than a TTI of an NB signal. As shown, the WBTTI 601 has a one symbol duration (e.g., one fourteenth of a millisecond(ms)), the WB TTI 602 has a two symbol duration (e.g., one seventh of ams), and the WB TTI 603 has a seven symbol duration (e.g., half a ms).Other durations are also possible.

FIG. 7 illustrates an embodiment micro-frame structure 700 for WBsignals. As shown, the durations of radio frames, subframes, and symbolsof WB signals may stay the same as those of legacy LTE radio frames,subframes, and symbols. A radio frame for the WB signal may be ten mslong and comprises ten subframes that each is one ms long. In anembodiment, each WB subframe may be further divided into micro-frames,for example into six, seven, eight, or some other number ofmicro-frames. A micro-frame may comprise six, seven, or some othernumber of symbols, depending at least partially on whether a guardinterval is needed between UL and DL micro-frames. A micro-framestructure, e.g. the number of symbols in the micro-frame and so on, maybe predetermined and/or based on a subframe index.

FIG. 8 illustrates an embodiment WB subframe 800. In this example, thefirst four micro-frames of the WB subframe 800 carry downlinktransmissions and the last two micro-frames of the WB subframe 800 carryuplink transmissions. Other configurations are also possible. As shown,the first UL micro-frame starts half a symbol duration (guard interval)after the last DL micro-frame. The last symbol may be uplink controlindicator (UCI) symbol reserved for carrying control information. Itshould be noted that the UCI symbol may be located elsewhere, e.g., thefirst symbol of the UL section of the subframe. Some acknowledgement andnegative acknowledgement indicators for hybrid automatic repeat request(HARQ) processes may be transmitted as HARQ-ACK bits in the UCI sent onthe physical uplink control channel (PUCCH).

Discussed above is one option to operate at higher frequencies and widerbandwidths for cellular systems. Another option is to use carrieraggregation (CA) to enable multiple 20 MHz carriers to fill theavailable bandwidths. FIG. 9 illustrates an embodiment WB signalstructure with carrier aggregation. As shown, a fifteen kHz backwardcompatible carrier (a legacy carrier) in a high frequency band may beaggregated with another non-backward compatible carrier. Thenon-backward compatible carrier may have a different sub-carrierspacing, e.g., sixty kHz, as shown in FIG. 9. The legacy carrier may beused to support legacy UEs or provide assistance for UEs to access thenew non-backward compatible carrier such as in initial access or randomaccess. For example, prior to transmitting a WB signal on resources of aWB micro-frame selected for the wideband signal, configurationinformation of the WB micro-frame may be transmitted to a UE over an NBsubframe. The benefit of this design includes that it just changes thecarrier frequency to the higher frequencies while maintaining the designfeatures of the current LTE system.

FIG. 10 illustrates a block diagram of an embodiment processing system1000 for performing methods described herein, which may be installed ina host device. As shown, the processing system 1000 includes a processor1004, a memory 1006, and interfaces 1010-1014, which may (or may not) bearranged as shown in FIG. 10. The processor 1004 may be any component orcollection of components adapted to perform computations and/or otherprocessing related tasks, and the memory 1006 may be any component orcollection of components adapted to store programming and/orinstructions for execution by the processor 1004. In an embodiment, thememory 1006 includes a non-transitory computer readable medium. Theinterfaces 1010, 1012, 1014 may be any component or collection ofcomponents that allow the processing system 1000 to communicate withother devices/components and/or a user. For example, one or more of theinterfaces 1010, 1012, 1014 may be adapted to communicate data, control,or management messages from the processor 1004 to applications installedon the host device and/or a remote device. As another example, one ormore of the interfaces 1010, 1012, 1014 may be adapted to allow a useror user device (e.g., personal computer (PC), etc.) tointeract/communicate with the processing system 1000. The processingsystem 1000 may include additional components not depicted in FIG. 10,such as long term storage (e.g., non-volatile memory, etc.).

In some embodiments, the processing system 1000 is included in a networkdevice that is accessing, or part otherwise of, a telecommunicationsnetwork. In one example, the processing system 1000 is in a network-sidedevice in a wireless or wireline telecommunications network, such as abase station, a relay station, a scheduler, a controller, a gateway, arouter, an applications server, or any other device in thetelecommunications network. In other embodiments, the processing system1000 is in a user-side device accessing a wireless or wirelinetelecommunications network, such as a mobile station, a user equipment(UE), a personal computer (PC), a tablet, a wearable communicationsdevice (e.g., a smartwatch, etc.), or any other device adapted to accessa telecommunications network.

In some embodiments, one or more of the interfaces 1010, 1012, 1014connects the processing system 1000 to a transceiver adapted to transmitand receive signaling over the telecommunications network. FIG. 11illustrates a block diagram of a transceiver 1100 adapted to transmitand receive signaling over a telecommunications network. The transceiver1100 may be installed in a host device. As shown, the transceiver 1100comprises a network-side interface 1102, a coupler 1104, a transmitter1106, a receiver 1108, a signal processor 1110, and a device-sideinterface 1112. The network-side interface 1102 may include anycomponent or collection of components adapted to transmit or receivesignaling over a wireless or wireline telecommunications network. Thecoupler 1104 may include any component or collection of componentsadapted to facilitate bi-directional communication over the network-sideinterface 1102. The transmitter 1106 may include any component orcollection of components (e.g., up-converter, power amplifier, etc.)adapted to convert a baseband signal into a modulated carrier signalsuitable for transmission over the network-side interface 1102. Thereceiver 1108 may include any component or collection of components(e.g., down-converter, low noise amplifier, etc.) adapted to convert acarrier signal received over the network-side interface 1102 into abaseband signal. The signal processor 1110 may include any component orcollection of components adapted to convert a baseband signal into adata signal suitable for communication over the device-side interface(s)1112, or vice-versa. The device-side interface(s) 1112 may include anycomponent or collection of components adapted to communicatedata-signals between the signal processor 1110 and components within thehost device (e.g., the processing system 1000, local area network (LAN)ports, etc.).

The transceiver 1100 may transmit and receive signaling over any type ofcommunications medium. In some embodiments, the transceiver 1100transmits and receives signaling over a wireless medium. For example,the transceiver 1100 may be a wireless transceiver adapted tocommunicate in accordance with a wireless telecommunications protocol,such as a cellular protocol (e.g., long-term evolution (LTE), etc.), awireless local area network (WLAN) protocol (e.g., Wi-Fi, etc.), or anyother type of wireless protocol (e.g., Bluetooth, near fieldcommunication (NFC), etc.). In such embodiments, the network-sideinterface 1102 comprises one or more antenna/radiating elements. Forexample, the network-side interface 1102 may include a single antenna,multiple separate antennas, or a multi-antenna array configured formulti-layer communication, e.g., single input multiple output (SIMO),multiple input single output (MISO), multiple input multiple output(MIMO), etc. In other embodiments, the transceiver 1100 transmits andreceives signaling over a wireline medium, e.g., twisted-pair cable,coaxial cable, optical fiber, etc. Specific processing systems and/ortransceivers may utilize all of the components shown, or only a subsetof the components, and levels of integration may vary from device todevice.

It should be appreciated that one or more steps of the embodimentmethods provided herein may be performed by corresponding units ormodules. For example, a signal may be transmitted by a transmitting unitor a transmitting module. A signal may be received by a receiving unitor a receiving module. A signal may be processed by a processing unit ora processing module. Other steps may be performed by a schedulingunit/module. The respective units/modules may be hardware, software, ora combination thereof. For instance, one or more of the units/modulesmay be an integrated circuit, such as field programmable gate arrays(FPGAs) or application-specific integrated circuits (ASICs).

Although the description has been described in detail, it should beunderstood that various changes, substitutions and alterations can bemade without departing from the spirit and scope of this disclosure asdefined by the appended claims. Moreover, the scope of the disclosure isnot intended to be limited to the particular embodiments describedherein, as one of ordinary skill in the art will readily appreciate fromthis disclosure that processes, machines, manufacture, compositions ofmatter, means, methods, or steps, presently existing or later to bedeveloped, may perform substantially the same function or achievesubstantially the same result as the corresponding embodiments describedherein. Accordingly, the appended claims are intended to include withintheir scope such processes, machines, manufacture, compositions ofmatter, means, methods, or steps.

What is claimed:
 1. A method comprising: selecting, by a base station, afirst micro-frame from a plurality of micro-frames in a subframe of afirst carrier for a first transmission, wherein the selected firstmicro-frame having a time duration that covers a first symbol of asecond carrier in a time-domain; scheduling, by the base station, thefirst transmission in the time duration of the selected firstmicro-frame in accordance with a signaling carried in the first symbolof the second carrier, wherein the first transmission is scheduled as adownlink transmission when the signaling is a downlink signaling, andwherein the first transmission is scheduled as an uplink transmissionwhen the signaling is an uplink signaling; and signaling, by the basestation, scheduling information of the first transmission to a userequipment (UE).
 2. The method of claim 1, wherein a combined duration ofthe plurality of micro-frames is equal to a duration of the subframe. 3.The method of claim 1, wherein the second carrier has a bandwidthoverlapping a portion of a bandwidth of the first carrier in a frequencydomain.
 4. The method of claim 1, further comprising: transmitting, bythe base station, configuration information of the plurality ofmicro-frames of the first carrier to the UE.
 5. The method of claim 1,wherein the first carrier is associated with a first numerology and thesecond carrier is associated with a second numerology different than thefirst numerology.
 6. The method of claim 5, wherein the first numerologyand the second numerology comprise different subcarrier spacings.
 7. Themethod of claim 1, wherein the first transmission is performed using asubcarrier spacing that is different than the signaling.
 8. A wirelessdevice comprising: a processor; and a non-transitory computer readablestorage medium storing programming for execution by the processor, theprogramming including instructions to: select a first micro-frame from aplurality of micro-frames in a subframe of a first carrier for a firsttransmission, wherein the selected first micro-frame having a timeduration that covers a first symbol of a second carrier in atime-domain; schedule the first transmission in the time duration of theselected first micro-frame in accordance with a signaling carried in thefirst symbol of the second carrier, wherein the first transmission isscheduled as a downlink transmission when the signaling is a downlinksignaling, and wherein the first transmission is scheduled as an uplinktransmission when the signaling is an uplink signaling; and signalscheduling information of the first transmission to a user equipment(UE).
 9. The wireless device of claim 8, wherein the second carrier hasa bandwidth overlapping portion of a bandwidth of the first carrier in afrequency domain.
 10. The wireless device of claim 8, wherein the firstcarrier is associated with a first numerology and the second carrier isassociated with a second numerology different than the first numerology.11. A method comprising: receiving, by a user equipment (UE), signalingthat schedules a first transmission in a time duration of a firstmicro-frame selected from a plurality of micro-frames in a subframe of afirst carrier, the time duration of the first micro-frame covering afirst symbol of a second carrier in a time-domain, wherein the firsttransmission is a downlink transmission when the first symbol of thesecond carrier is configured to carry a downlink signaling, and thefirst transmission is an uplink transmission when the first symbol ofthe second carrier is configured to carry an uplink signaling.
 12. Themethod of claim ii, wherein a combined duration of the plurality ofmicro-frames is equal to a duration of the subframe.
 13. The method ofclaim ii, further comprising: receiving, by the UE, configurationinformation of the first carrier.
 14. The method of claim 13, whereinthe configuration information comprises bandwidth, subcarrier spacing,or a center carrier frequency of the first carrier.
 15. The method ofclaim ii, wherein the second carrier has a bandwidth overlapping aportion of a bandwidth of the first carrier in a frequency domain. 16.The method of claim ii, wherein the first carrier is associated with afirst numerology and the second carrier is associated with a secondnumerology different than the first numerology.
 17. The method of claim16, wherein the first numerology and the second numerology comprisedifferent subcarrier spacings.
 18. A wireless device comprising: aprocessor; and a non-transitory computer readable storage medium storingprogramming for execution by the processor, the programming includinginstructions to: signaling that schedules a first transmission in a timeduration of a first micro-frame selected from a plurality ofmicro-frames in a subframe of a first carrier, the time duration of thefirst micro-frame covering a first symbol of a second carrier in atime-domain, wherein the first transmission is a downlink transmissionwhen the first symbol of the second carrier is configured to carry adownlink signaling, and the first transmission is an uplink transmissionwhen the first symbol of the second carrier is configured to carry anuplink signaling.
 19. The wireless device of claim 18, wherein thesecond carrier has a bandwidth overlapping a portion of a bandwidth ofthe first carrier in a frequency domain.
 20. The wireless device ofclaim 18, wherein the first carrier is associated with a firstnumerology and the second carrier is associated with a second numerologydifferent than the first numerology.